Sorry about my previous post, I made a mistake there.
To disable system updates within ujust upgrade, you need to edit a specific file. In this case, topgrade looks for a config file in /usr/share/ublue-os/topgrade.toml. You need to add “system” to the disable list.
That should make ujust update ignore system updates specifically. After that, just make Gnome is not updating the system on its own.
Just note that this file might be modified by the system, I’m not sure whether a system update may change this file in the future.
You can also disable the toggle like you stated, but that might also disable distrobox and other auto-updates
It doesn’t work that way, the nvidia drivers are baked into the image itself. But you could just stay on your old image and run flatpak update by hand if you want to keep the apps up to date.
Then when the next nvidia driver drops give that a shot.